/*
 * Copyright (c) 2010 Curtis Boyden.  All rights reserved. 
 * This software was developed by Curtis Boyden and is provided under the terms 
 * of the GNU Lesser General Public License, Version 2.1. You may not use 
 * this file except in compliance with the license. If you need a copy of the license, 
 * please go to http://www.gnu.org/licenses/lgpl-2.1.txt. The Original Code is ejMud
 * (Ewerp Java MUD).  The Initial Developer is Curtis Boyden.
 *
 * Software distributed under the GNU Lesser Public License is distributed on an "AS IS" 
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or  implied. Please refer to 
 * the license for the specific language governing your rights and limitations.
*/

package com.ewerp.mud.commands;

import java.util.concurrent.LinkedBlockingQueue;

import com.ewerp.mud.core.exceptions.EwerpMudException;
import com.ewerp.mud.core.plugin.IPlugin;
import com.ewerp.mud.lifecycle.ILifecycleListener;
import com.ewerp.mud.plugin.IPluginManager;

public class EwerpCommandEngine implements IPlugin, ICommandEngine, ILifecycleListener, Runnable {
    
    protected static EwerpCommandEngine instance = new EwerpCommandEngine();
    
    protected IPluginManager pluginManager;
    
    protected LinkedBlockingQueue<ICommand> commandQueue = new LinkedBlockingQueue<ICommand>();
    
    protected EwerpCommandEngine() {
    }
    
    public static EwerpCommandEngine getInstance() {
        if(instance == null) {
            instance = new EwerpCommandEngine();
        }
        return instance;
    }
    
    @Override
	public Class<?>[] getInterfaces() {
		return new Class<?>[] { ICommandEngine.class };
	}
    
    @Override
    public void pushCommand(ICommand command) throws EwerpMudException {
        try {
            if(command != null) {
                commandQueue.put(command);
            }
        } catch (Exception e) {
            throw new EwerpMudException("Unable to push command onto the stack", e);
        }
    }

    @Override
    public void init() {
    }

    @Override
    public void pause() {
    }

    @Override
    public void start() {
        (new Thread(this)).start();
    }

    @Override
    public void stop() {   
    }
    
    @Override
    public void run() {
        while(true) {
            try {
                ICommand cmd = commandQueue.take();
                cmd.setPluginManager(pluginManager);
                cmd.execute();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void setPluginManager(IPluginManager pluginManager) {
        this.pluginManager = pluginManager;
    }
}
